Interpolators can be useful for address translation, but only with CPUs, no PIO, no DMA.
Regarding QSPI Flash, it depends on timing ... you can run the program in RAM, disable XIP, and use QMI interface in direct mode (I've done that with RP2040, even directly driving the pins at max speed by CPU, unfortunately those pins are not accessible to PIO). It's going faster (and predictable) for single byte random access. Actually, I think it could work through DMA chaining with PIO, not sure. I have had to use the CPU anyway (and Interpolator, which now got better doing rotate instead shift) Image may be NSFW.
Clik here to view.
But if ROM image fits in RAM, then it's easy.
Overclocking will come in handy, if you have to do some other processing through CPU.
Regarding QSPI Flash, it depends on timing ... you can run the program in RAM, disable XIP, and use QMI interface in direct mode (I've done that with RP2040, even directly driving the pins at max speed by CPU, unfortunately those pins are not accessible to PIO). It's going faster (and predictable) for single byte random access. Actually, I think it could work through DMA chaining with PIO, not sure. I have had to use the CPU anyway (and Interpolator, which now got better doing rotate instead shift) Image may be NSFW.
Clik here to view.
But if ROM image fits in RAM, then it's easy.
Overclocking will come in handy, if you have to do some other processing through CPU.
Statistics: Posted by gmx — Sun Sep 29, 2024 10:09 pm
